Question

If a double stranded DNA has 35% thymine, what would be the percentage of guanine in the DNA.

• A. 35%
• B. 70%
• C. 30%
• D. 15%

Answer 1

The correct option is D 15%

According to Chargaff's rule,

A=T and G=C.

The percent composition of thymine according to the question is 35%.

Adenine=Thymine=35%

(%Adenine+%Thymine) + (%Cytosine+%Guanine) = 100%

(35+35) + (C+G) = 100%

(C+G)= 30%

Since C=G,

C=G=15%